Show HN: AlgoDrill – Interactive drills to stop forgetting LeetCode patterns

still 17 spots left

I understand that it's a sales tactic, but it's lying to your users worth it?

what a terrible future

Thanks for taking the time to try it and write this up.

You are right that the current check still leans too much toward my reference solution. It already ignores formatting and whitespace, but it is still quite literal about structure and identifiers, which nudges you toward writing my version instead of your own. There are many valid ways to express the same idea and I do not want to lock people into only mine.

Where I want to take it is two clear modes. One mode tracks the editorial solution for people who want to learn that exact version for an interview, while still allowing harmless changes like different variable names and small structural tweaks. Another mode is more flexible and is meant to accept your own code as long as it is doing the same job. Over time the checker should be able to recognise your solution and adapt its objectives and feedback to what you actually wrote, instead of pushing you into my template. It should care more about whether you applied the right logic under time pressure than whether you matched my phrasing.

There is also a small escape hatch already in the ui. If you completely blank or realise you have missed something, you can press the Stuck button to reveal the reference line and a short explanation, so you still move forward instead of getting blocked by one detail.

You are pushing exactly on the area I plan to invest in most. The first version is intentionally literal so the feedback is never vague, but the goal is for the checker to become more adaptive over time rather than rigid, so it can meet people where they are instead of forcing everyone through one exact solution.

Some might consider that a kind of commentary on the leet code interview format.

This by itself completely un-sold me. Requiring such rote memorization is a hard pass for me, it seems the user should just be able to self-assess whether they got it “right” (like Anki cards).

> We know for a fact that most of the people that master intellectual problems do so via pattern recognition, not by reasoning.

Where is this fact stated, and who are "we" here? Sounds like an opinion or guess at best.

> Not really understanding the negativity here

There are two comments that could be read negativily, the rest is neutral or positive. I don't really understand the constant need for people to bring up what (they think) the rest of the comments said. Post your piece adding positivity if you want, but most of the time comments end up a fair mix so any time someone adds a snippet like that, it turns outdated in a few hours.

Thank you, I really appreciate you signing up.

I agree with you on pattern recognition. AlgoDrill is built around taking patterns people already understand and turning them into something their hands can write quickly under pressure. You rebuild the solution line by line with active recall, small objectives, and first principles explanations after each step, so it is more than just memorizing code.

You are also right about the language gap. Right now the drills are Python first, but I am already working on full support for JavaScript, Java, and C++ across all problems, and I will have all of those in by the end of this year. I want people to be able to practice in the language they actually use every day, so your comment helps a lot.

> Not really understanding the negativity here. We know for a fact that most of the people that master intellectual problems do so via pattern recognition, not by reasoning.

> The lifetime membership + launch discount was a good marketing bait I felt for.

The negativity here with me is because it feels like clickbait and like a scammy ad to manipulate me into purchasing.

It is almost lying. I find it unethical and I don't think there are 17 lifetime access spots, it's just artificial hype that doesn't make sense to me.

Marketing (at least like this) is basically lying.

I don't know if I feel any negativity, but this is the first time I actually thought 'the price of subscription is approximately equal the price of Opus tokens needed to build a custom version of this for myself'... and got a bit scared TBH

Agree with your overall message, but I don't think thats true for chess. Chess players wouldnt be spending an hour on their own move in a match where theyve been been studying the board for hours already if it were that simple

> Not really understanding the negativity here.

In the last year or so HN seems to have attracted a lot of people (plus some bots) who seem to have been socialized on Reddit.

I don't know if these people are ignorant of what a good discussion forum can be (because they've never experienced one) or just don't care, but I do wish we could see more reflection on the second-order impacts of posting, and a move away from the reflexive negativity that mimics the outer face of good criticism while totally missing the thought and expertise good criticism requires.

That is fair. I went with Google first because it let me ship the first version quickly, but for a tool aimed at developers GitHub and simple email sign in make much more sense.

I am working on both and plan to let people move their account once they are live if they would prefer not to use Google here.

I was hooked, but don't have a Google account anymore. Oh well…

That is a good first approximation, but it is a bit more guided than a plain Anki deck. For each problem there is a structured study page and an interactive practice mode.

NeetCode 150 is a popular curated list of LeetCode problems that covers the core interview patterns people expect nowadays, like sliding window, two pointers, trees, graphs, and dynamic programming. I used that set as the base so you are not guessing which problems to focus on, and more problems and patterns are being added on top of that core set regularly.

On the study side, each problem has a consistent structure with the core idea, why that pattern applies, and a first principles walkthrough of the solution. On the practice side, the solution is broken into small steps. Each step has a clear objective in plain language, and you rebuild the code line by line by filling in the missing pieces. After you answer, you see a short first principles explanation tied to the line you just wrote, so you are actively recalling the logic instead of just reading notes.

You can repeat problems and patterns as much as you want, mark problems as solved or unsolved, and filter by pattern so you can focus on the ones you struggle with most. There is not a full automatic review schedule yet. For now you choose what to review, and the goal is to use that progress data to track weak patterns, guide what you should drill next, and add more types of focused drills over time.

> imaginary problem instead of doing something for yourself

they're doing it for themselves just like when they solve sudokus, crosswords or play fortnite

I do codeforces in my spare time. Sometimes I implement and ML paper. Other times, I like to slog through my implementation of Raft, Paxos and VR. Not everybody wants to build generic crud app number 1,200,674. Coding is for solving problems, the problems might be engineering or just pure fun.

some people like to play with Rubiks Cubes, which among other things is a nice tactile way to learn some interesting advanced math

Seeing how other people solve problems opens up new ways for me to solve my own. Many people are not RTFM but instead want applied examples.

this type of stuff is generally for interviews. But it does tell you that the candidate has learned the patterns in question. That particular solution isn't important, but knowing good design patterns to solutions is. Knowing how a decent number of problems are best solves gives them a good intuition of how to tackle problems. Otherwise, they would tackle it using their intuition/vibes. There are books one can read to learn this stuff as well I'm sure, but how do you prove what knowledge you've retained?

10 programmers will write 10 different ways to solve a simple problem. and that code is tech-debt other programmers have to maintain at some point. Just having coders that have the same base-level memorized problem solving patterns can ease that pain, and it can make collaboration/reviews easier down the road.

Nice comparison. It is pretty similar in spirit to the woodpecker method.

In chess you repeat the same positions until the patterns feel automatic. Here it is LeetCode problems. You keep seeing the same core patterns and rebuild the solution step by step. For each step and line there is a small objective first, and then a short first principles explanation after you answer, so you are not just memorizing code but training pattern recognition and understanding at the same time.